Monday, May 18, 2015

Carputer 2015 - Sourcing Parts

When I began this car computer project, I imagined that the current popularity of hobbyist embedded computing and custom A/V projects would make it easy to obtain components. Not so much. Internet searches and scouring forums can lead toward the specific products that will work best for a project, but many of these products will not be available from a domestic distributor.

Be prepared to work directly with distributors in Asia. Some of these distributors may have a web site for ordering, some work through eBay, and some just have an email address. It helps to respect that English is not the first language and to keep communication simple and clear. Payment is generally accepted through PayPal and timely shipping may cost a bit. I have so far dealt with four different Asian distributors and have received correct and functioning components each time.

Expect a lot of parcels like this one.

The apparent cheapest solutions to problems may not actually be the cheapest. One of my initial project guidelines was to start with inexpensive components and be able to justify price increases. Having done this, I can now offer advice to others who may be considering a similar project.

  1. Don't buy an EasyCAP / EzCAP for composite video capture from Linux. You could spend a fortune in money, time, and frustration to get a combination of device and kernel that actually works. Spend the money and get a UVC capture device from +Andy FEBON.
  2. Don't settle for a cheap TN display panel or resistive touchscreen overlay. An IPS panel with capacitive touchscreen gives the true "tablet experience" that most people expect. I finally found what I was looking for at Chalkboard Electronics.
Left good (FEBON100 UVC), right bad (EasyCAP).

The US$56 TN panel and resistive touchscreen setup below is pretty much only useful for prototyping. I certainly wouldn't want to have to use it.

Cheap TN panel and resistive touchscreen.

Below is the 7" IPS panel that I will install in my car. The pictures don't do it justice. The display controller is small and affixed to the back of the panel. Entire unit can be powered over USB! Full information here.

IPS panel in direct lighting.
IPS panel in indirect lighting.

I'm now just waiting on a powered USB3 hub and some cables before being able to demo this system in my car. A number of commenters have mentioned that it's hard to grasp what I'm trying to achieve with this project. My next posting should contain a demo video that makes things much more clear.